Learn

Learn: room acoustics & diffuser design

No acoustics degree required. Short, practical guides that explain the ideas behind the panels Fresnelcut builds — so you know what you're cutting and why.

Fundamentals

What is a quadratic-residue diffuser?A plain-English explanation of the quadratic-residue diffuser (QRD): what the wells do, why the depths follow n² mod N, and when to use one.Diffuser vs absorber: what's the difference?Diffusers scatter reflections; absorbers remove energy. Learn which one fixes echo, which fixes boom, and when to use both.

Choosing

QRD vs PRD vs skyline: which diffuser do you need?Compare the three main Schroeder diffusers — quadratic-residue, primitive-root, and 2-D skyline — and pick the right one for your room.

Design

How deep should diffuser wells be?Well depth is set by the design frequency and the number of wells. Here's the formula, a worked example, and how stock thickness limits your low end.Where to place diffusers in a roomFirst reflection points, the rear wall, and ceiling clouds — a practical guide to where diffusers help most, and where to use absorption instead.

Ready to build one? Browse the diffuser & absorber types or open the designer.